Furnace.



N. FROST.

FURNAUB. APPLIUATION FILED NOV. 10, 1910.

2 SHEETS-SHEET 2.

Patented Feb. 27, 1912.

v INVENTOI? MJ, wa/@ UNITED' STATES PATENT opcion;

NATHAIEI. FROST, F nLooiviINGToN, lILLINors.

Application filed November l To all whom fmag/ concern I. `Be it `known that I, NATiiAivisL Fnos'r, a 'citizen of the nited' States, anda residentiof Bloomington. in the county 'of McLean f and State of Illinois, have invented a nevvj and 'Improved Furnace, oi. which the toll lowing is a full, clear, and exactdescription, My invention relates to certain impro ments in furnaces for use in heating,lr am,

` andrelates more particularly to that type 1: of furnacein which the air is exhausted to fidw `backwardly and forwardly through conduits or `passageways before being -delivered to the smoke stack. i

In one type of horizontal furnace there i @has beenv employed a fire box with a. rear 'ward extension presenting corrugated sides and, terminating in av back breeching. From the upper end of this breeching a plurality ot conduits extend forwardly'over the fire .il-)ox and at apoint above the forward end oic the latter to connect with a rearwardlyextendine, horizontally-disposed smoke pipo. XVithin these parts is a casingj through which passes tlie air to'be heated.

` One object oiimy invention is to increase, the heating" efl'ectiipon air at. the time tltte dampersj are open to lrive the lire` a direct draft.` S

'30 Another object of my invention is to provide certain improvements in the smoke pipe. whereby `greater life and more eiiicientservice will be secured therefrom.

The other objects and adyan'tages of my' improved construction willf be more fully set forth hereinafter and pointed out in the claim. i t

Reference is to be had to the accompanyiupr drawings lorniingrl a pant of this speci- 40 iication. in which similar chlaracters of irgef- *jerence indicate correspondiiig parts in tall. the views, and i whichM l i Figure 1 is a side elevation of a furnace, constructed in accordance 1,with my inven- 445 tion, a portion thereof being broken away Y- i tov show the interiors of'tlie irekboX and smoke pipe; Fig. 2 is al transverse `section on the line 2--2 of Fig. `1;.1l`iggn 3 is a perspective View of the backl breeching; and

Fig. 4 is a top plan Viennot.l a portion of the fire boX. y A

In the specific" hot air`fiirnace illustrated `in the vaccompanying drawifngs there is provided a fire box 10 havi-iiig grate bars 11 .and two separate rearward extensions 12 and 13 from this tirebox, the tv voextensions oon- Specioation of Letters Patent.

t Fortunes.`

io, i910. serial No, 591,566.

stitutincr conduits and separated by a partition 13a. At their rear ends these partitions connect to a one-piece back breecliing 1l, illustrated in perspective iny Fig. 3. This back breeching has an outwardlyextending flange by which it 'isl bolted to the rear end of the tire box extension passages 12 and 13,

,and has two upwardly-extending branches 15` and` 1(5"connected with tlietivo passages 12 andl 13, respectively. These branches' at their upper ends each has a Vfront wall 1T,

apertiired for communication with separate forwardly-extending conduits 18., In the specific form illustrated there are employed three of these conduits upon each side, al* though the particular number-is not important.Y At their front ends all of these conduits 18 connect to a transversely-extending chamber 19 disposed' above the front end of the fire box.` This chamber has a `larafe central aperture by which itcoininunicates with a smoke pipe 20` extending.r rearwardly be tween thes'eparate sets of conduits. Broadly speaking, these parts and their relative ar rangement are old in the art.

Patented Feb. 27, 1912;V

I have illustrated an arrangement parts, wherebythe smoke and gases of coinbustion flowing rearwardly from the fire ho'x through the passages12 and 13'niay enter the smoke pipe adjacent the rear end of the furnace to establish a direct draft without i passing through tie conduits 18 and the horizontal section 2l) and the portion of the smoke pipe therebetween. In furnaces o: this character it has been common to estab'- lish a direct draft communication between the front end of the tire box and the chamloer 19 directly thereabove. lThe flames and hot gases do n'ottlow through the passages 12 and -13 or along the sides et the re box, instead theycome directly forward and into the smoke pipe, so that there is very little heat efect upon the air Within the casing inclosing the furnace. In my improved con struction, I provide a back breeching with acentral vpassage 21 between the two` branches 15 and 16` and in communication with both the` passages 12 and 13. This central passage 21 communicates with the smoke pipe at a point between the two branches 15 and 16 of the breeching, and Within the smoke pipe is a damper 22 for controlling communication.

The damper 22 may be operated in any suitable manner, but, as illust-rated., it out curved fornito fit the lower surface of' the lil@ gated castiron sections 24. These sections smoke pipe and is connected to a rod 23 extending forwardly ythrough the smoke pipe of the chamber 19 to the front end of the furnace, as is illustrated in Fig. 1. Upon opening the direct draft in my improved furnace to temporarily increase the rate of combustion tlie damper 22 is pulled forwardly to open the passage 21, and the flames may then flow from the tire box rearwardlythrough the passages '12 and 13 to the passage 21 and then into the smoke pipe. In do'ing so the flames vand gases are caused to travel over the corrugated sides of the lire box and of the passages 12 and 13 so that the latter are heated and radiate the heat to the surrounding air. The draft is direct, but at the same time the most iniportant element of the radiating surface is in operation llieii it is desired to c'ut out the direct draft thepassage2l is closed and the gases flow rearwardly through the passages 12 and 13, then forwardly through the conduits 18l and then rearwardly again through the smoke pipe 20 to obtain from the hot gases the maximum amount of' heat.

Further illustration. involves the lconstruction of the side Walls of the firc bo.\ and of the passages 12 and 13. This Wall substantially semicylindrical in form and is made up of. a plurality of separate corrusubstantially meet .alongthe vtop and are v sections on one sideare not in alinement` witli'the Joints in the sections on the oppo,`

4provided with'iianges by which the sections on each side are bolted at the ridge to those on the opposite side. Preferably Iso form these sections that'the joints between the site side. Thus each section on one side is posite side,'as is clearly indicated in Figi/L Ihre increases the strength and rigidity of. the furnace and preventsthe joints from bolted to two separate sections upon ythe op'- breaking or being separated dueto the expansion and contraction undergone during the temperature changes.` y

Instead of forming thejsmoke pipe of sheet metal, as is customary in furnaces of this character, I forni it o f-seini..cylindrical lcast liron sections 25 rigidly bolted together' and provided-With a joint 26, `as .indicated in Fig. 1, t-ol providefor the expansion and contract-ion of the parts.` The tianges which heat to the air.

In the tire box I, I may also provide ra plurality of side lining sections 27 of fire clay or other suitable refractory material, and so construct thesections that they fit into the lower portioiiof the corrugations of the side walls of the tire box and yalso vided with slots 28 .or apertures which .lead

through to the space beneath the grates so that the liningpieces constitute a portion of f' the horizontal supporting surface of the firev bed and increase the effective area of the grates and'promot'e combustion.

Having thus described my invention, I claim as new and desire to secure by Letters Patent: 1-

`A furnace having a irebox and having its rear portion divided to form passages, a one-piece hollow back breeching communieating at its lower portion With said passages and bifurcated vto form upwardly-exn tending spaced branches and a portion between the lower ends ofthe branches, constitutiiig a saddle and having an opening communicating with the interior of the breeching, a hollow front. breeching, conduits extending from said branches of said hack breechiiig to the side portions of the front breeching, a smoke pipe normally open to thefront breeching and extending rearwardly therefrom between the said branches of ,the back breeching, said smoke pipe having an opening coinciding with thel y NATHANIEL FROST.

Witnesses:

' L. K. I-IEALY,

l". J. It'oAcH. 

